Outboard motor



July 23, 1940- J. JOHNSON ET AL OUTBOARD MOTOR Filed Nov.. 16, 1935 5 Sheets-Sheet 1 v f by w m w 5/ L. J. JOHNSON ET AL 2,209,301

OUTBOARD MOTOR- July 23, 1940.

5 Sheets-Shaft 3 Filed Nov. 16, 1935 $011115 Lib/2725072, HarrgL. Ja/z 72607;,

1940. L. J. JOHNSON El AL ,3 1

OUTBOARD MOTOR Filed Nov. 16, 1935 5 Sheets-Sheet 4 Iozzw J Johrzaorz, f/czrrg/LJofzrzaoxz.

OUTBOARD MOTOR Filed NOV. 16, 1935 5 Sheets-Sheet 5 ZomJJohrzsa/z Harry LJo/zrzaan,

M. flow/ ow 45 this invention as applied to the transom of a not only improves the motor appearance but also Patented July 23, 1940, h I

UNITED STATESVPATENT OFFICE A 2,209,301 OUTBOARD M01303 Louis J. Johnson and Barry L. Johnson, Wankegan, 11L, asslgnors to Johnson Brothers Engineering Corporation, Waukegan, 111., a corporation or Indiana Application November 16, 1935, Serial No. 50,127

38 Glaims. (Cl.-115-l8) 'This invention relates in general to an out- Fig. 4 is a transverse scctional view through board motor of the type mounted for steering the power head; about a vertical axis and tiltable about a hori- Figs. 4 5, 6, '7, 8 and 9 are sections taken on zontal axis, and has more particular reference to the lines 4 4, 6-5, t-G, 88, and 9-9 the detailed construction of the supporting, enrespectively of Fig. 3; I closing, driving, cooling and other component Fig. 10 is a section of the'lower bracket supparts. D

Among the important objects of the invention Figs. 11 and 12 are sections taken on the lines are: to provide an improved support for mount- H-ii and i2l2 respectively of Fig. 10; 10 ing the motor about a vertical axis other than the Fig. 13 is a section through the shock absorber driving axis, forward of the power head and be-- taken on the line 13-93 of Fig. 3; I low the top of a boat to which it is applied; to Fig. 14 is a vertical section through the drive provide a, tilting axis near the top and in advance shaft casing; of the power head and the steering axis; to Fig. 15 is a top view of the drive shaft casing 15 provide improved means for detachably mountshown in Fig. 14; 1

ing an outboard motorin fixed permanent braclr- Fig. 16 is a sectional view of the lower end ets attached to a boat; to provide a power head of the drive shaft casing with the skeg removed; enclosure substantially water-tight but with open- .Figs. 1'? and 18 are sections taken on the lines ings for air and exhaust with doors for accesi'i-i'l and |8I8 respectively of Fig. 16;

2o sibility and with drip connections at the bottom; Fig. 19 is a side elevation with parts in section 2 to provide a motor casing of smooth symmetriillustrating an improved detachable mounting; -cal lines attached between the power head and Fig. a. sectional view of the detachable the lower unit; toprovide a lower unit which locking device at the bottom oi the pivot pin embodies a combined drive shaft casing, mufshown in Fig. 3;"

fier, exhaust and cooling pipe container; to pro= Fig. 21 is a section of the steering handle or 2 vide a drive shaft casing having a shock absorber tiller taken on the line 28-2! of Fig. 19; I cavity separate from the interior of the casing Fig. 22 is a face view of the lower fixed bearwhich constitutes a muiiier chamber; to provide ing bracket shown in Fig. 19;

a drive shaft casing having improved means Fig. 23 shows the upper fixed bearing bracket so for supporting and installing the drive and proas shown in Fig. 19; 3.

peller shafts therein; to provide an improved ex-= Fig. 24 illustrates a carrying handle;

haust cut-out actuated by the operation of the Fig. 25 illustrates the operating lever forthe propeller and a water cooling line therefrom; to fluid pressure cut-out shown in Fig. 19; and provide easy steering; to reduce weight and costs; Fig. 26 is a section of the bearing clamp taken to provide up and down adjustment of the motor on the line of Fig. 19.

and to improve the appearance of the outboard Among the advantages claimed for outboard motor by confining it substantially within the motors in accordance with the presentinvenforward and aft lines of a boat; and in'general tion are a reduction of weight, a reduction of to produce the outboard motor structure herein noise because the power head is installed rear- 49 shown and described. wardly of the transom, and a reduction 05 ex 4 In the accompanying drawings illustrating the pense in providing a motor which is not necespreferred and modified forms of the invention; sarily of the full pivot steering type. Locating Fig. 1 is a side elevation with some parts in the power head, including the fly-wheel, below section, of an outboard motor in accordance with or practically below the upper edge of the transom boat; lowers the center of gravity and makes a boat I Fig. 1 is a fragmentary view showing a fuel more stable and less likely to overturn. A motor tank in the boat and its connection to the motor of this structure is easy to steer; 'it has less parts power head; subject to salt water corrosion; it provides more 50 Fig. 2 is a top view of the construction shown eflicient underwater structure and more emclent s in Figure 1; propeller water pumping; and provides a more Fig. 3 is a sectional view of the motor shown in substantial lower unit. Enclosing the power head, Fig. 1; except the fly-wheel magneto, further improves Fig. 3 is a sectional assembly of a. quick takethe appearance, makes more pleasing the lines down pivot tube and fixed boat brackets; of the motor itself and of a boat to which it is f;

liapplied, reduces the noise from the power head and makes the power head less subject to defects of operation due to water splashing and exposure of the parts-without sacrificing any necessary adjustment which is easily effected by a projecting part or through doors provided in the eas- 1 Referring more particularly to the drawings,

the Dower head comprises 'an engine and a. flywheel magneto, said engine having a vertical crank shaft and adjacent. parallel cylinders 3| fired alternately and enclosed by a casing 32, the upper end of the crankshaft projecting above i the casing and supporting a flywheel magneto 33 and a rope starter plate. 34.

Secured together are the engine, the casing .32, and the lower unit casing 35, said casings 32 and 35 forming a; single casing, the casing 32 having a portion clampedbetween the engine and the lower. um't casing 35. Said casing 35 houses a vertical drive shaft 36 and a horizontal propeller shaft 31 connected to the drive shaft by gears and 39. g

To-mount the outboardmotor shown in Figs. 1 and 3 for tilting and steering, a pivot tube 4| 5 is rigidly fixed by a pin 42 in a bracket 43 attached to the motor. The tube has an upper pro-- jecting portion for the attachment of a handle 44 ins.

which extends forwardly into a boat for steerand a downwardly projecting portion 1 mounted in a split clamp 45 of a pivoting bracket 46 attachable to a boat transom with an interposed bearing tube 41 of rubber or the like, and

with metal and rubber washers .48 at the'top of the clamp 45 between it and the brackets 43.

I Said casing 32 is clamped between the bracket 43 and the engine.

The pivoting bracket 46 is mounted upon a horizontal pivot 49 (see Figs. 2 and 3) carried by the boat attachment bracket 50 between its paral lei arms, which may be of the conventional removable type as shown in Figs. 1 and 3, having an inside clamping 'screw 5| and lower outside thrust socket arms 52, and removable with the motor from the transom 53 of a boat.

In being thus attached to the upper portion of the engine rather than to a .bearing surrounding the shaft below the engine it is possible to position the outboard motor at a relatively low position with respect to the top of the boat, which is I further lowered in regular outboard motor boats by providing a recess 54 in the upper edge of the transom, in which the attachment bracket 50 is 3 silient sleeve .41. I The casing 32 surrounds the power head and aordinarily seated.

Extending forwardly from the casing 35 are spaced projections 55 in which a tube 56 is of rubber or other suitable material for cushioning the vibration of themotor with respect to the boat, which is also one of the functions of the recover 32 as shown in Fig. 19, or a partial cover 32 as shown in Fig. 1, is attached-thereto at intervals by fastening-screws 63. As shown in Fig.

3 the bottom 32 of a fuel tank 12 may form a partial cover for the casing. Around the top adjacent the upper crank shaft bearingbut benath the magneto flywheel is an opening 64 for the admission of air for combustion, which is substantially splash-proof because it is covered and overlapped by the magneto 33. Thecasing is preferably of smooth symmetrical and unbroken 1ines, narrow'er at the front as shown in Fig.4, to permit a maximum swing for steering,

At the rear end of the casing isan extension 65 having a hinge 66 at one side of a rear opening 61 and a hook 68 at the other side to close the extension over spark plugs 69 at the ends of the cylinders 31.

The casing also encloses a carbureter 10 at one side of the engine which is adjacenta hingeddoor' have an adjustment arm or lever Ni -accessible from the outside of the casing.

A fuel tank 12 may be supported on top of the casing 32 forming a portion of the cover of the casing. with a forward recess 13 partially embracing the magneto 33. It has a fill pipe 14 adjacent the upper rear end and a fuel pipe 15 (see also Fig. 4) extending at the side of. the engine inside of the casing 32 with a hand-valve 16 within the casing and accessible through the door 1| for controlling the supply of fuel to the carburetor 10. This fuel tank is alsosmooth and symmetrical in outline. and'stream-lined in shape. It projects-only slightly above the'rear end of a boat to which the engine is applied. A- fuel tank 12 as shown in Fig.' 1 may be located within the boat and connected to the carburetor by a fuel pipe line I5 through the fitting at the bot-.

, tom of the casing 32, the fuelline preferably extending over the transom recess 54 and connected to the. tank 12 by a shut-oif valve 12F.

The"lower unit casing 35 is preferably a hollow unitary casting formed with a recess II, in the top for receiving a shock absorber and with a tubular extension 16 to provide a bearing for the drive shaft 36. -The lower portion of the casing is thin, substantially stream-lined from front to rear exhaust extension 36 having atop opening -8l which extends to one, side as shown in Fig. 15, and communicates with the engine exhaust passage-32 for directing the products of combustion downwardly into the hollow casing 35. Above the propeller 46 thecasing 35 arches the upper portion of the path of travel of the propeller blade on both sides thereof providing an exhaust passage 83 which terminates in a discharge opening 84 behind and below. theanti-cavitation plate which extends above and 'rearwardly thereof.

Withinthe casing 35, is a tube 65 having its lower end extending through the wall of the passage 33 directly to the rear of the upper path of travel of the' propeller blades for receiving .cooling water therefrom and directing it to the water jacket of the engine from whence it is returned through a pipe 86 extending through the a rubber bearing sleeve I II within the support casing 35 and having its lower end terminating in the forward side of the upper path of travel of the propeller blades so that the cooling water for the engine is circulated through the pipes 05 and 06 by the propeller.

Another water pipe 81 extends from the rear side of the propeller arch upwardly in the casing and has a hook 88 at its upper end turned downwardly against the lower muffler extension to provide a cooling water spray forced by the propeller-40 through the tube 01 and discharging from the upper end thereof to condense the hot gases from the engine and to cool the interior of the casing, the water pipes, and the engine, shaft therein.

The shaft 36 is mounted in a bearing 89 at the top of the casing and in a bearing 90 at the bottom of the casing. Between the reduced or thinner lower portion of the casing in which there is a sleeve 9| loosely surrounding the shaft 38 and the upper bearing extension it, the shaft is preferably enclosed in a separate sleeve 92 which protects it from direct contact with any hot gases in the mufiier or the upper portion of the casing 35. I

In the lower end of the casing 35 the propeller shaft 37 is positioned at right angles to the shaft 35 and has an end bearing 93 seated in a socket 0 5 in the casing. In the bottom of the propeller shaft housing is an opening closed by a cover 9'5 to which the skeg 30 is attached. To install the shaft 36 the cover 95 is removed, the shaft is inserted from the bottom, and the propeller shaft 3? is then placed in position meshing the gears 32 and 30 and attaching the propeller thereto in a well known manner.

At the upper end of the shaft 36 is a shock absorber seated in the recess or cavity ll and ccmprising a short shaft section 97 secured to the lower end of the engine crank shaft and rotatable with it. A collar 98 (see Figs. 3 and 13) attached to the top shaft section and a collar 95) attached to the drive shaft 30 in this cavity each have two projections 180 apart between which four pieces lilll of rubber are inserted with a 'casing 395 attached to the upper collar and surrounding the rubber pieces which holds them in place' and prevents oil from the bearing coming in contact with the rubber. In the bottom of the recess iii is a drain opening M2 for any oil or water. 'Zhis shock absorber is light, inexpensive and affordsprotection for the shaft driving gears 33 and 3e, shear pin and other parts. It is easily accessible by removing the power head from the lower unit. For installations with this type oi shock absorber the propeller All is provided with a frangible shear pin H03 which connects it with propeller shaft 3?.

In the structure shown in Figure 19 a number of different features are shown. The bearing for steering consists of a single pivot tube Hid;

the boat mounting comprises upper and lower fixed brackets I05 and I05; the muflier casing is provided with an automatic exhaust outlet closed by the cooling water; a steering-ban e has a shake-proof connection; the fuel tank is omitted from the motor and a separate fuel tank may be provided as in Fig. 1 A simple carrying handle I0! is also shown which may be applied toany motor.

The pivot tube I08 is clamped tightly in'a tilting bracket I08 by a split clamp I09 so that it does not turn therein. The upper end of the tube extends through washers H0 and through ing bracket 2 of the motor, and a split steering handle 3 is clamped by screw H3 for fric tional adjustment on the upper end of the tube 'I0l, the tiller handle having spaced sides I25 (see Fig. 21) between which extends a projection I26 from the motor bracket II! with a spring H4 between the projection and each side of the handle to cushion the steering movement; to absorb the torque shock, and to prevent the vibration of the motor from being transmitted through to the steering handle. Thus the motor is turned about the axis of the tube I04 with resultant easy steering because of the small diameter of the pivot shaft I04. m; the top of the tube I00 is a -limiting collar I|5held in place by a pin Md.

At the lower end of the tube ll is a quick takedown catch (see Figs. 3, 3 and 20) consisting of a collar Ill having a slot H8 in which a locking arm H0 is pivoted. This arm has aprojection I 20 adapted to engage a milled slot III in the side of the tube where it is held in yielding engagement by a spring I22 attached to the collar Ill. To remove the catch it is rotated in either direction until the projection I20 rides out of the slot Ifii whereupon the catch may be moved endwise of and removed from the tube. 1

In the construction illustrated in Figure 19, the engine casing 32 and the drive shaft housing i2; form a casing. In said construction the casing 32 is clamped between the drive shaft housing SH and the engine, and is also clamped between the engine and the bracket I00.

Instead of the quick take-down pivot tube ll structure being assembled with the removable bracket construction of Fig. 3, it is preferably combined with supporting brackets I05 and I00 permanently attached to a boat transom 53 as shown in Fig. 3 with the locking device Ill at the lower end of the pivot tube 4I.- The tiller I20 may also be attached to the tube M by the shakeproof handle structure shown in Fig. 21. To remove the quickly detached structure it is necessary only to release and slip ofi th locking device Hill, and to raise the motor until the tube 5i slips out of the "tilting clamp I08. Similarly the pivot tube i8 5 may be assembled with a bodily removable boat bracket 50 as shown in Fig. 3, if desired.

The lower end of the pivot tube extends a distance below the lower thrust bracket I00 and intermediate the ends of the tube are transverse holes 823 so that the motor may be raised for adjustment and held in position by inserting a pin in either one of the openings I23 above the tilting clamp I69, and the tube is adjustable up and down with the motor for vertical adjustment of the propeller, and is held in any adiusted position by the clamp I09.

The stem brackets I05 and I08 are rigidly attached to a boat transom 53, the tilting bracket I08 is mounted upon a horizontal pivot pin I24 and the motor is turnable forsteering' by means ofthe handle I I3 which has a pivot forward hand grip extension I20 which projects into the boat. A control lever I29 with an ignition stop button I30 extends from the magneto adjacent and above thehandle 3 where. it is freely accessible and movable for varying the speed, and the button for stopping the motor.

An automatic exhaust cut-out (Figs. 19 and 25) is mounted upon a plate I3I secured in an openin: adjacent the upper end of the lower casing 7 SDI unit and comprising a lever I32 mounted in ears I33 projecting inwardly from the plate and one end of the lever having an enlarged extremity I34 disposed directly opposite the downwardly bent end I35 of the cooling water tube 31 and having {a spring I35 installed between the other end of the lever and the inside of the plate I3I which tends to press the enlarged end I34 toward the bent tube end I35. In the plate I3I is an exhaust l0 opening I31 and a closure I38 pivoted to the plate has a link- I39 connecting it to the lever I 32 be-' tween its pivotal point and the enlarged end sothat the spring I36 tends to press the closure I38 to open position and the water driven up the tube 15 81 and impinging the enlarged end I34 of the ;lever is sufficient to overcome the spring and {close the atmospheric cut-out. Thus when the motor is starting the exhaust is opened to at- 'mosphere but after the motor is running the 20 propeller pumping water through the tube 81 a'ctuates the lever I3I to close the atmospheric exhaust outlet and to keep it closed under normal running conditions. If the cut-out is opened during ordinary running conditions, it is an in- 25 ,dication that the propeller pump may not be operating properly to cool the engine.

A simple carrying handle III! for any motor of this kind comprises a plate I40 (Fig. 24) havinga central opening I 4|, the material of which is 30 curled about one edge to form a rounded grip I42 and the opposite edge is provided with perforations I43 throughwhich fastening bolts. I44 are inserted for securing it to a suitable portion f the motor. 36 1 With this type of motor it may be also desirable to install the fuel tank within the boat with. out a gravity feed as indicated in Fig. 1 and to i use a hand pressure pump, or pressure from. the

lmotor to raise the fuel to the, carburetor, In

40 many boats the sheer line is high enough so that the fuel tank may be installed to use a gravity feed.

In operation, the outboard motors .as shown herein are installed upon the transom of a boat 45 ieither by means of a detachable bracket, or by fixed brackets and a detachable vertical pivot pin about which the motor is rotated on an axis diiferent from that of the crank shaft for steer- :ing; the motor is started by a rope starter wound 50 m connection with the starter plate, and the adjustment of the carburetor is made from the top or through the opening in the casing; the :speed is controlled bythe carburetor and the ignie tion'handle which also carries a circuit breaker ujbutton .for short circuiting the current sup- .1 ply to the spark plugs. The features of novelty gin the construction and operation of the motor :are set forth in the description and as the operation of these parts is either therein set forth or 50 clearly apparent, no further description of the ioperation is believed necessary. 1 It is however an important structural feature .that 'the motor is so mounted that it is rotatable ;for steering upon a ,pivot in advance-of the motor, 65 which makes it possible to mount the power head well below the top of a boat transom to which I it is attached, thereby lowering the center of gravity of the at, and that by enclosing the ipower head in a splashproof casing which is of '70 smooth and unbroken lines, a motor of more pleasing appear nce is produced, the noise due Ito the engine 0 ration is reduced, and in fact jthenoise is practically eliminated by the enclos- ;ingcasing and-the underwater exhaust. The' I} power head casing and the drive shaft housing are in effect the unitary casing extending from a level substantially at the top of the boat to the region of the propeller, protecting the motor from splash even though the entire power plant is at a low level. 6 The structural features. above described also are designed and intendedto reduce the labor and expense in assembling the parts which are greatly reduced in number by adopting a unitary lower casing which combines with it a mufiier l0 chamber and discharge passages for the engine exhaust. This casing design requires that the 7 interior thereof be cooled in order to protect the drive shaft and the cooling arrangement shown additionally operates an atmospheric exhaust cut-out and improves engine operation by condensing the exhaust vapors.

1. In a marine power plant, in combination, a. power head including an internal combustion engine, an elongated propeller shaft housing secured to said head, a supporting bracket adapted to be secured to the stern of a boat, said supporting bracket and said power head having cooperating portions for swingingly carrying said power head about an axis substantially parallel with and forwardly of said elongated housing,v said cooperating portions including an elongated cylindrical member disposed within an enclosing member permitting the quick detachment of said power head from and-attachment to said supporting bracket, and readily releasable'means for preventing the accidental detachment of said power head-from said supporting bracket.

2. A marine power plant comprising a power head, a.propeller shaft housing extending downwardly from said head, said head includinga water-cooled internal combustion engine, a fly wheel above said engine, said power head having on its upper surface an air intake for combus- I tion air, said fly wheel being disposed above said air intake-:in' protecting relationship with said air mtake to guard said intake against splashes of water.

3. A marine power plant having a power head including an internal combustion engine, an elongated drive shaft housing secured to said head, a drive shaft within said housing operatively connected with said power head, a propeller operatively connected with said driveshaft. supporting means for swingingly mounting said power plant about an axis forwardly of said power head, tiller means for swinging said power plant comprising-rod means pivoted about said axis. and means connecting said rod means to saidiis power head comprising cushioning means between said rod means and said power head.

4. A' marine power plant having a power head. an elongated drive shaft housing secured to said head, a drive shaft within said housing operm atively connected with said power head, a pro-. peller operatively'connected with said drive shaft, supporting means for swingingly mounting said power plant about an axis forwardly of said power head and approximately Pa allel with said 05 drive shaft, said supporting means including a non-rotatable cylindrical member. tiller means having adjustable frictional clamping relation--. ship. with said cylindrical member. and cushioning means between .said power head and said tiller means.

' 5. In a marine power plant, in combination. supporting means adapted to be secured to the stern of a boat, said supporting means including a cylindrical member,. a power head, a drive shaft housing secured to said power head, said cylindrical member being disposed forwardly of said power head and said housing, said power head and housing being rotatably mounted with respect to the axis of said cylindrical member, and cushioning means embracing said cylindrical member for reducing vibration shocks set up by said power head.

6. In a marine power plant, in combination, supporting, means adapted to be secured to the stern of a boat, said supporting means including a cylindrical member, a power head, a drive shaft housing secured to said power head, said cylindrical member being disposed forwardly of said power head and said housing, said power head and housing being rotatably mounted with respect to the axis of said cylindrical member, tiller means swung about the axis of said cylindrical member, and cushioning means between said power head and said tiller means for reducing vibration shocks set up by said power head. I

7. In a marine power plant, in combination, supporting means adapted to be secured to the stern of a boat, said supporting means including a non-rotatable cylindrical member, a power head, a drive shaft housing secured to said power head, said cylindrical member being disposed forwardly of said power head and said housing, said power head and housing being rotatably mounted with respect to the axis of said cylindrical member, tiller means swung about the axis of said cylindrical member, cushioning means between said power head and said tiller means for reducing vibration shocks set up by said power head, and means for adjusting the frictional engagement betweensaid tiller means and said cylindrical member.

8. In a marine power plant, in combination, supporting means adapted to be secured directly to the stern of a boat, said supporting means including a freely tilting bracket, apower head, a drive shaft housing secured to said power head, and a cylindrical member secured to said power head forwardly of said power head and said housing, said cylindrical member having rotatable relationship with said bracket.

9. In a marine power plant, in combination, supporting means adapted to be secured to the stern of a boat, said supporting means including a tilting bracket, a power head, a drive shaft housing secured to said power head, and a cylindrical member secured to. said power head forwardly of said power head and said housing,

said cylindrical member having rotatablev rela-' tionshipv with said bracket, said cylindrical member having a readily detachable abutmentmember adjacent to its lower extremity for limiting upward movement of said power plant relative to said bracket.

10. In a marine Dower plant, in combination supporting means adapted to be secured to the stern of a boat, said supporting means including a tilting bracket, a power head, a drive shaft housing secured to said power head, a cylindrical member secured to said power head forwardly of said tilting portion and said housing, said cylindrical member having rotatable relationship with said bracket, and tiller means swung about the axis of said cylindrical member, said tiller means including cushioning means reacting with respect to said power head.

11. In a marine power plant, 'in combination, imvporflng means adapted to be secured to the stern of a boat, said supporting means including a tilting bracket, a power head, a drive shaft housing secured to said power head, a cylindrical .member secured to said power head forwardly of said tilting bracket and said housing, said cylindrical member having rotatable relationship with said bracket, and tiller means swung about the axis of said cylindrical member, said tiller means including cushioning means reacting with respect to said power head, said tiller means having adjustable frictional clamping relationship with said cylindrical member.

12. In a marine power plant, in combination, supporting means adapted to be secured to the stern of a boat, said supporting means including a tiltable bracket and also including a cylindrical member, a power head, a drive shaft housing secured to said power head, said cylindrical member being disposed forwardly of said power head and said housing, said power head and housing being rotatably mounted with respect to the axis of said cylindrical member and being mounted upon said cylindrical member, and adjustment means for adjusting the longitudinal position of said cylindrical member with respect to said bracket.

13. In a marine power plant, in combination, a power head, a drive shaft housing secured thereto, means for supporting said power plant at a relatively low level from the stern of a boat, a casing for said power head for protecting said power head from water splash, said head including an internal combustion engine having a carburetor and a fiy-wheel, the upper portion of said casing comprising a cover, said cover comprising a fuel tank, said casing having an intake for combustion air located below and in position to' be protected by said fiy-wheel.

14. The combination, in a marine 'motorsystem with an exhaust passage provided with an under water discharge port and an above water discharge port, of means for closing said above water discharge port, means for directing cooling water from the propeller of said system to other parts thereof, said closing means for said above water discharge port being responsive to the force of the water in said cooling water directing means.

,15. A marine power plant having a power head,

'an elongated drive shaft housing secured to said head, a drive shaft within said housing operatively connected with said power head, a propeller operatively connected with said drive shaft, supporting means for swingingly mounting said power plant about an axis forwardly of said power head and approximately parallel with said drive shaft, said supporting means including a cylindrical member adapted to be fastened to the transom ofa boat, and tiller means adapted to turn said power plant and having adjustable clamping relationship with said cylindrical member.

16. A marine power plant having a power head, an elongated drive shaft housing secured to said head, a drive shaft within said housing operatively connected with said power head,.a propeller operatively connected with said drive shaft, supporting means for. swingingly mounting said power plant about an axis forwardly ofsaid power head and approximately parallel with said drive shaft, said supporting means including a cylindrical member adapted to be fastened to the transom of a boat, tiller means adapted to turn said power plant and having adjustable clamping relationship with saidcylindrical member,

" and cushioning means between said power head and said tillermeans.

'17. The combination with a boat of a casing pivoted thereto for steering and hinged for upward movement, and a driving motor mounted'in the casing, extending below the casing and tending to press the lower part of the casing toward the boat. v

18. In a device of the character described, the combination with a boat transom, of a bracket applied thereto and including a horizontal pintle, a bracket element mounted thereon, a vertical pintle carried by said bracket elemen and a casing pivoted on said vertical pintle or dirigible .and tilting movement with respect to said boat and adapted to house a boat propelling device mounted in said casing exteriorly of said boat.

19."I'l'ie combination with a boat havin transom, of a casing aft thereof, means providing a fulcrum adjacent the transom on which said casing and transom are pivotally connected for relative swingingw movement in a vertical plane,

said means having a second substantially upright fulcrum connecting it with said casing for accommodating pivotal movement of said casing bodily in a horizontal plane-an engine housed within the casing and supported therein, to partake of the two movements thereof, and an engine driven propelling means carried by the casing and operatively connected with the engine, said casing having thrust transmitting means for limiting the movement of the casing about said first mentioned fulcrum in the direction of thrust of said propelling means. v

20. The combination with, a boat having a I transom, of a transom bracket provided with a transversely extending. fulcrum adjacent said transom, means pivoted on said transverse fu crum providing an upright fulcrum aft thereof,

casing means provided on said upright fulcrum and having a portion beneath both of said ful crums for transmitting forward thrust to said boat, an engine housed within said casing and supported thereby to partake of the movement of said casing about both of said fulcrums, and engine driven propelling means carried by the casing and operatively connected 'with the engine,

said casing being oscillatable for steering about.

said upright fulcrum and being oscillatabl'e about said transverse-fulcrum to clear submerged obstacles.

21. The combination with a boat having a transom, of a transom bracket provided with a transversely extending fulcrum adjacent said .transom, means pivoted on said transverse fulcrum providingan, upright fulcrum aft thereof, casing means provided on said upright fulcrum;-

and having a portion beneath both of said fulcrums for transmitting forward thrust to said .boat, an-engine housed within said casing and "supported thereby. to partake of the movement of said casing about both of said fulcrums, and engine driven propelling means carried by the casing.and operatively connected with the engine,

7 said casing being oscillatable for steering about said upright fulcrum. and being oscillatable' about said transverse fulcrum to clear submerged obstacles, the portion of said casing connected with said upright fulcrum comprising substane 'tially'thetop forward: part thereof, whereby the top of said casing is substantially at the level of the top of said transom ands aid engine is dis- '7o posed substantially-wholly-below said level.

22. In a device-of the character described; the combination with a transom bracket having a transom-engaging portion, of ,a. casing 'having' a top substantially at the level of said' portion, 7 means hingedly connecting said casing top with said transom bracket portion, an engine housed within said casing below the top thereof and provided with an upright drive shaft projecting downwardly, propelling means operatively connected with said drive shaft to receive motion therefrom, said propelling means being located vertically below a part of said casing, said casing having a portion below its hinged connection with said bracket in a position for thrust transmitting cooperation with the transom of a boat on which said bracket is suspended.

23. In a device of the character described, the combination with a boat transom, of a casing -having a top portion substantially at the top level of said transom, means providing a hinged connection on a transverse fulcrum between said casing and said transom, an engine mounted within said casing, said casing providing a sub stantially complete enclosure therefor, a propeller rotatable upon a horizontal axis and disposed directly beneath a portion of said casing. and driving connections from said engine to said propeller extending'substantially vertically downwardly, said casing being adapted to exclude water from said engine,'and said casing and tran- -som being adapted to baiiie the transmission of engine noise to the boat.

.24. A thrust member for limiting forward tilting -movement of a marine power plant relativean internal combustion engine including the spark plugs and carburetor thereof, a drive shaft extending downwardly from said engine, a drive shaft housing for said shaft connected to, said engine, and a splash-proof casing for said engine having an opening for combustion air and means, for preventing access of splash through said tween said engine and said. drive shaft housing. 26. A power plant comprising, in combination,

opening,said casing being secured in place be-.'

an internal combustion engine including thespark plugs and carburetor thereof, a drive shaft extending downwardly from said engine, a drive shaft housing for said shaft connected to said engine, and a splash-proof casing for said engine having an opening for combustion air and means for preventing access of splash. through said opening; said. casing being secured in place between said engine and said drive shaft hous- Qing.

' 27. In combination, a power plant including an internal combustion engine, enclosure means enclosing saidengine, a drive shaft housing extending downwardly from said engine, said enclosure and said-housing being assembled to form a casing, and supporting means. for tiltably supporting said power plant, said'enclosure'being clamped between said supporting means and said engine'and between said engine and said drive shaft housing.

' 28. In combination, a power; plant including an internal combustion engine, enclosure means en'- closing said engine, a drive shaft housing extending downwardly from said engine, said enclosure we I .nd said housing being assembled to form a casng, supporting means for tiltably supporting aid power plant, said enclosure being clamped letween said supporting means and said engine aid between said engine and said drive shaft rousing, said enclosure being a splash-proof nember having an opening for combustion air. ind baille means for obstructing admission of vater splash through said opening.

29. In combination, a power plant including an nternal combustion engine, enclosure means en- :losing said engine, a drive shaft housing extendng downwardly from said engine, said enclo- ;ure and said housing being assembled to form L casing, and supporting means for tiltably sup- 'Jorting said power plant, said enclosure being :lamped between said supporting means and said engine and between said engine and said drive shaft housing, said engine having a fly-wheel, ;aid enclosure being a splash-proof member havng an opening for combustion air, said fiy-wheel wing in position to obstruct admission of water ;plash through said opening.

30. A marine power plant comprising, in combination, a power head including an internal :ombustion engine, a drive shaft housing secured to said power head, said drive shaft housing including a portion normally disposed above the water line of said plant, said portion of said drive shaft housing embodying an expansion chamber which occupies a substantial proportion of said drive shaft housing above said normal water line, the lower portion of said housing having a passage for discharging gases from said expansion chamber to a region below the normal water line of said power plant, and means for supporting said power head and said drive shaft housing, said supporting means including a vertical pivot the axis of which is disposed forwardly of said head and said housing for swingingly mounting said power plant for steering functions whereby to permit a housing of sufficient size to function as an expansion chamber.

31. A marine power plant comprising, in combination, a power head including an internal combustion engine, a drive shaft housing secured to said power head, said drive shaft housing including a portion normally disposed above the water line of said plant, said portion of said drive shaft housing embodying an expansion chamber which occupies a substantial proportion of said-drive shaft housing above said normalwater line, said housing having an opening for discharging gases from said expansion chamber, and means for supporting said power head and said drive shaft housing, said supporting means including a vertical pivot the axis of which is disposed forwardly of said power head and said housing for swingingly mounting said power plant for steering functions whereby to permit a housing of sumcient size to function as an expansion chamber.

32. A marine power plant comprising, in combination, a power head including an internal combustion engine, a drive shaft housing secured 'to said power head, said drive shaft housing inof said drive shaft housing above said normalwater line, the lower portion of said housing hav-' ing a passage for discharging gases from said expansion chamber to a region below the normal water line of said power plant, means for supporting said power head and said drive shaft housing, said supporting means including a vertical pivot the axis of which is disposed forwardly of said head and said housing for swingingly mounting said power plant for steering functions whereby to permit a housing of sufficient size to function as an expansion chamber, conduit means for delivering cooling water against the inner surface of said expansion chamber, means providing an above water outlet for exhaust gasesvdrive shaft housing embodying an expansion chamber which occupies a substantial proportion of said drive shaft housing above said normal water line, said housing having an opening for discharging gases from said expansion chamber, means for supporting said power head and said drive shaft housing, said supporting means including a vertical pivot the axis of which is disposed forwardly of said power head and said housing for swingingly mounting said power plant for steering functions whereby to permit a housing of sufficient size to function as an expansion chamber, an envelope surrounding said drive shaft to protect said shaft, and water conduits for carrying water propelled by said propeller, certain of said conduits delivering water to said power head for cooling purposes, another of said conduits being positioned to discharge water to the inner surface of said expansion chamber.

34. A marine power plant comprising, in combination, a power head including an internal combustion engine, a drive shaft housing secured to said power head, said drive shaft housing including a portion normally disposed above the water line of said plant, said portion of said drive shaft housing embodying an expansion chamber'which occupies a substantial proportion of said drive shaft housing above said normal water line, said housing having an opening for discharging gases from said expansion chamber, means for supporting said power head and said drive shaft housing, said supporting means ineluding a, vertical pivot the axis of which is disposed forwardly of said power head and said housing for swingingly mounting said power plant for steering functions whereby to permit a housing of sufficient size to function-as an expansion chamber, an envelope surrounding aid drive shaft for protecting said drive shaft, and conduit means to discharge water against the interior s rface of said expansion chamber.

35. A power plant and mounting means therefor including a power head, a drive shaft housing secured to said head and extending downwardly therefrom, a propeller at the lower portion of said drive shaft housing, means for swingingly mounting said power plant from the stern of a boat about a vertical axis disposed forwardly of said power plant, said supporting means including cylindrical means swingable with said head and shaft, said cylindrical means being positioned to take the thrust against the stern of a.v

boat under normal operative conditions.

36. The combination with. a boat ofa casing pivoted .thereto for steering and hinged for up-.

ward movement, and a driving motor mounted in IE the casing extending below the casing and tending to press the lower part of the casing toward the boat, said casing embodying a splash-proof member for protecting said driving motor against water splash.

37. In a marine power plant, in combination, a power head, a drive shaft housing secured thereto, means for supporting said power plant at a relatively low level from the stern of a boat, a

casing for said power head for protecting said power head from watersplash, said head including an internal combustion engine including the carburetor thereof, the upper portion of said casing comprising a. cover, and a fly-wheel for said motor, said casing having an intake for combustion air located below and in position to be protected by the said fly-wheel.

38. A power plant comprising, in combination,

an internal combustion engine, a drive shaft extending downwardly from said engine, a drive shaft housing for said shaft connected to said engine, a drive shaft housing for said shaft connected to said engine, and a splash-proof casing ill 

